<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
    div{
        width: 100px;
        height: 100px;
        border: 2px solid red;
    }
        #d1{
            margin: 50px;/*四个方向都是50px的外边距*/
            /*margin: 50px 100px;*/
            /*margin: 10px 20px 30px 40px;*/
        }
        #d2{
            margin-top: 100px;
        }
        #s1{
            /*行内元素上下外边距无效*/
            margin-bottom: 100px;
            margin-right: 100px;
        }
        #s2{
            margin-left: 50px;
        }
    </style>
</head>
<body>
<span id="s1">span1</span>
<span id="s2">span2</span>
<div id="d1">div1</div>
<div id="d2">div2</div>
</body>
</html>